Factor scalac provider

WORKSPACE

@@ -15,6 +15,10 @@ load("@com_github_bazelbuild_buildtools//buildifier:deps.bzl", "buildifier_depen
 
 buildifier_dependencies()
 
+load("//scala:toolchains.bzl", "scala_register_toolchains")
+
+scala_register_toolchains()
+
 load("//scala:scala.bzl", "scala_repositories")
 
 scala_repositories()

private/example/App.scala

@@ -0,0 +1,5 @@
+object App extends scala.App {
+  def version = scala.util.Properties.versionString
+
+  println(s"hello, world from $version!")
+}

private/example/AppTest.scala

@@ -0,0 +1,9 @@
+import org.scalatest._
+
+class AppTest extends FlatSpec with Matchers {
+  it should "have a successful test" in {
+    System.err.println(s"hello, world from ${scala.util.Properties.versionString}!")
+
+    App.version should be (scala.util.Properties.versionString)
+  }
+}

private/example/BUILD.bazel

@@ -0,0 +1,26 @@
+load(
+    "@io_bazel_rules_scala//scala:scala.bzl",
+    "scala_binary",
+    "scala_library",
+    "scala_test",
+)
+
+scala_library(
+    name = "library",
+    srcs = glob(
+        ["*.scala"],
+        exclude = ["*Test.scala"],
+    ),
+)
+
+scala_binary(
+    name = "app",
+    main_class = "App",
+    runtime_deps = [":library"],
+)
+
+scala_test(
+    name = "test",
+    srcs = ["AppTest.scala"],
+    deps = [":library"],
+)

private/example/WORKSPACE

@@ -0,0 +1,27 @@
+load("//repositories:bazel_skylib.bzl", "load_bazel_skylib")
+
+load_bazel_skylib()
+
+load("//repositories:rules_jvm_external.bzl", "load_rules_jvm_external")
+
+load_rules_jvm_external()
+
+load("//repositories:rules_scala.bzl", "load_rules_scala")
+
+load_rules_scala()
+
+load("//repositories:rules_proto.bzl", "load_rules_proto")
+
+load_rules_proto()
+
+load("//repositories:rules_python.bzl", "load_rules_python")
+
+load_rules_python()
+
+load("@io_bazel_rules_scala//scala:toolchains.bzl", "scala_register_toolchains")
+
+scala_register_toolchains()
+
+load("@io_bazel_rules_scala//scala:scala.bzl", "scala_repositories")
+
+scala_repositories()

private/example/repositories/bazel_skylib.bzl

@@ -0,0 +1,11 @@
+"""load skylib"""
+
+load(":tools.bzl", _github_release = "github_release")
+
+def load_bazel_skylib():
+    _github_release(
+        name = "bazel_skylib",
+        sha256 = "97e70364e9249702246c0e9444bccdc4b847bed1eb03c5a3ece4f83dfe6abc44",
+        repository = "bazelbuild/bazel-skylib",
+        release = "1.0.2",
+    )

private/example/repositories/rules_jvm_external.bzl

@@ -0,0 +1,11 @@
+"""load rules_jvm_external"""
+
+load(":tools.bzl", _github_archive = "github_archive")
+
+def load_rules_jvm_external():
+    _github_archive(
+        name = "rules_jvm_external",
+        repository = "bazelbuild/rules_jvm_external",
+        sha256 = "62133c125bf4109dfd9d2af64830208356ce4ef8b165a6ef15bbff7460b35c3a",
+        tag = "3.0",
+    )

private/example/repositories/rules_proto.bzl

@@ -0,0 +1,11 @@
+"""load rules_proto: needed by protobuf repo"""
+
+load(":tools.bzl", _github_archive = "github_archive")
+
+def load_rules_proto():
+    _github_archive(
+        name = "rules_proto",
+        repository = "bazelbuild/rules_proto",
+        sha256 = "62847ac7740865d73a2c8199be292bba913d62e79084442f3e829c3058a25e64",
+        tag = "d7666ec475c1f8d4a6803cbc0a0b6b4374360868",
+    )

private/example/repositories/rules_python.bzl

@@ -0,0 +1,11 @@
+"""load rules_python: needed by protobuf repo"""
+
+load(":tools.bzl", _github_archive = "github_archive")
+
+def load_rules_python():
+    _github_archive(
+        name = "rules_python",
+        repository = "bazelbuild/rules_python",
+        sha256 = "7d64815f4b22400bed0f1b9da663037e1578573446b7bc78f20f24b2b5459bb9",
+        tag = "38f86fb55b698c51e8510c807489c9f4e047480e",
+    )

private/example/repositories/rules_scala.bzl

@@ -0,0 +1,7 @@
+"""link back to parent rules_scala repo"""
+
+def load_rules_scala():
+    native.local_repository(
+        name = "io_bazel_rules_scala",
+        path = "../..",
+    )

private/example/repositories/tools.bzl

@@ -0,0 +1,28 @@
+"""helpers for to remove http_archive boilerplate
+
+N.B.: doesn't currently include the bazel mirros
+"""
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+def github_release(name, repository, release, sha256):
+    (org, repo) = repository.split("/")
+    http_archive(
+        name = name,
+        sha256 = sha256,
+        urls = [
+            "https://github.com/{repository}/releases/download/{release}/{repo}-{release}.tar.gz".format(repository = repository, repo = repo, release = release),
+        ],
+    )
+
+def github_archive(name, repository, sha256, tag):
+    (org, repo) = repository.split("/")
+    without_v = tag[1:] if tag.startswith("v") else tag
+    http_archive(
+        name = name,
+        sha256 = sha256,
+        strip_prefix = "{repo}-{without_v}".format(repo = repo, without_v = without_v),
+        urls = [
+            "https://github.com/{repository}/archive/{tag}.zip".format(repository = repository, tag = tag),
+        ],
+    )

scala/BUILD

@@ -1,29 +1,86 @@
-load(
-    "@io_bazel_rules_scala//scala:providers.bzl",
-    _declare_scalac_provider = "declare_scalac_provider",
-)
+load("//scala:bootstrap_toolchain.bzl", "bootstrap_toolchain")
 load("//scala:scala_toolchain.bzl", "scala_toolchain")
+load("//scala:test_toolchain.bzl", "test_toolchain")
+
+# default toolchains registered by `scala_register_toolchains`
+
+# bootstrap toolchain
+
+toolchain_type(
+    name = "bootstrap_toolchain_type",
+    visibility = ["//visibility:public"],
+)
+
+bootstrap_toolchain(
+    name = "bootstrap_toolchain_impl",
+    classpath = [
+        "@io_bazel_rules_scala_scala_library",
+        "@io_bazel_rules_scala_scala_reflect",
+    ],
+    macro_classpath = [
+        "@io_bazel_rules_scala_scala_library",
+        "@io_bazel_rules_scala_scala_reflect",
+    ],
+    repl_classpath = [
+        "@io_bazel_rules_scala_scala_library",
+        "@io_bazel_rules_scala_scala_reflect",
+        "@io_bazel_rules_scala_scala_compiler",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+toolchain(
+    name = "bootstrap_toolchain",
+    toolchain = ":bootstrap_toolchain_impl",
+    toolchain_type = "@io_bazel_rules_scala//scala:bootstrap_toolchain_type",
+    visibility = ["//visibility:public"],
+)
+
+# standard toolchain
 
 toolchain_type(
     name = "toolchain_type",
     visibility = ["//visibility:public"],
 )
 
 scala_toolchain(
-    name = "default_toolchain_impl",
+    name = "toolchain_impl",
+    scalac = "//src/java/io/bazel/rulesscala/scalac",
     scalacopts = [],
     visibility = ["//visibility:public"],
 )
 
 toolchain(
-    name = "default_toolchain",
-    toolchain = ":default_toolchain_impl",
+    name = "toolchain",
+    toolchain = ":toolchain_impl",
     toolchain_type = "@io_bazel_rules_scala//scala:toolchain_type",
     visibility = ["//visibility:public"],
 )
 
+# test toolchain
+
+toolchain_type(
+    name = "test_toolchain_type",
+    visibility = ["//visibility:public"],
+)
+
+test_toolchain(
+    name = "test_toolchain_impl",
+    visibility = ["//visibility:public"],
+)
+
+toolchain(
+    name = "test_toolchain",
+    toolchain = ":test_toolchain_impl",
+    toolchain_type = "@io_bazel_rules_scala//scala:test_toolchain_type",
+    visibility = ["//visibility:public"],
+)
+
+# unused dependency checker toolchain
+
 scala_toolchain(
     name = "unused_dependency_checker_error_toolchain_impl",
+    scalac = "//src/java/io/bazel/rulesscala/scalac",
     unused_dependency_checker_mode = "error",
     visibility = ["//visibility:public"],
 )
@@ -41,24 +98,6 @@ java_import(
     visibility = ["//visibility:public"],
 )
 
-_declare_scalac_provider(
-    name = "scalac_default",
-    default_classpath = [
-        "@io_bazel_rules_scala_scala_library",
-        "@io_bazel_rules_scala_scala_reflect",
-    ],
-    default_macro_classpath = [
-        "@io_bazel_rules_scala_scala_library",
-        "@io_bazel_rules_scala_scala_reflect",
-    ],
-    default_repl_classpath = [
-        "@io_bazel_rules_scala_scala_library",
-        "@io_bazel_rules_scala_scala_reflect",
-        "@io_bazel_rules_scala_scala_compiler",
-    ],
-    visibility = ["//visibility:public"],
-)
-
 java_library(
     name = "PlaceHolderClassToCreateEmptyJarForScalaImport",
     srcs = ["PlaceHolderClassToCreateEmptyJarForScalaImport.java"],

scala/bootstrap_toolchain.bzl

@@ -0,0 +1,27 @@
+BootstrapInfo = provider(
+    doc = "BootstrapInfo",
+    fields = [
+        "classpath",
+        "macro_classpath",
+        "repl_classpath",
+    ],
+)
+
+def _impl(ctx):
+    toolchain = platform_common.ToolchainInfo(
+        bootstrapinfo = BootstrapInfo(
+            classpath = ctx.attr.classpath,
+            macro_classpath = ctx.attr.macro_classpath,
+            repl_classpath = ctx.attr.repl_classpath,
+        ),
+    )
+    return [toolchain]
+
+bootstrap_toolchain = rule(
+    _impl,
+    attrs = {
+        "classpath": attr.label_list(mandatory = True, allow_files = True),
+        "repl_classpath": attr.label_list(mandatory = True, allow_files = True),
+        "macro_classpath": attr.label_list(mandatory = True, allow_files = True),
+    },
+)

scala/plusone.bzl

@@ -10,7 +10,7 @@ PlusOneDeps = provider(
 )
 
 def _collect_plus_one_deps_aspect_impl(target, ctx):
-    if (ctx.toolchains["@io_bazel_rules_scala//scala:toolchain_type"].plus_one_deps_mode == "off"):
+    if (ctx.toolchains["@io_bazel_rules_scala//scala:toolchain_type"].scalainfo.plus_one_deps_mode == "off"):
         return []
     export_plus_one_deps = []
     for exported_dep in getattr(ctx.rule.attr, "exports", []):

scala/private/common_attributes.bzl

@@ -98,11 +98,6 @@ implicit_deps = {
     "_java_runtime": attr.label(
         default = Label("@bazel_tools//tools/jdk:current_java_runtime"),
     ),
-    "_scalac": attr.label(
-        default = Label(
-            "@io_bazel_rules_scala//src/java/io/bazel/rulesscala/scalac",
-        ),
-    ),
     "_exe": attr.label(
         executable = True,
         cfg = "host",

scala/private/coverage_replacements_provider.bzl

@@ -74,7 +74,7 @@ def _is_enabled(ctx):
     if "@io_bazel_rules_scala//scala:toolchain_type" not in ctx.toolchains:
         return False
     else:
-        return ctx.toolchains["@io_bazel_rules_scala//scala:toolchain_type"].enable_code_coverage_aspect == "on"
+        return ctx.toolchains["@io_bazel_rules_scala//scala:toolchain_type"].scalainfo.enable_code_coverage_aspect == "on"
 
 coverage_replacements_provider = struct(
     aspect = _aspect,

scala/private/macros/scala_repositories.bzl

@@ -199,3 +199,18 @@ def scala_repositories(
         name = "io_bazel_rules_scala/dependency/scala/guava",
         actual = "@io_bazel_rules_scala_guava",
     )
+
+    native.bind(
+        name = "io_bazel_rules_scala/dependency/scalac_rules_commons_io",
+        actual = "@scalac_rules_commons_io",
+    )
+
+    native.bind(
+        name = "io_bazel_rules_scala/dependency/scala/scalatest/scalatest",
+        actual = "@io_bazel_rules_scala_scalatest",
+    )
+
+    native.bind(
+        name = "io_bazel_rules_scala/dependency/scala/scalactic/scalactic",
+        actual = "@io_bazel_rules_scala_scalactic",
+    )

scala/private/phases/phase_collect_jars.bzl

@@ -15,7 +15,7 @@ load(
 
 def phase_collect_jars_scalatest(ctx, p):
     args = struct(
-        base_classpath = p.scalac_provider.default_classpath + [ctx.attr._scalatest],
+        base_classpath = ctx.toolchains["@io_bazel_rules_scala//scala:bootstrap_toolchain_type"].bootstrapinfo.classpath + [ctx.attr._scalatest],
         extra_runtime_deps = [
             ctx.attr._scalatest_reporter,
             ctx.attr._scalatest_runner,
@@ -25,13 +25,13 @@ def phase_collect_jars_scalatest(ctx, p):
 
 def phase_collect_jars_repl(ctx, p):
     args = struct(
-        base_classpath = p.scalac_provider.default_repl_classpath,
+        base_classpath = ctx.toolchains["@io_bazel_rules_scala//scala:bootstrap_toolchain_type"].bootstrapinfo.repl_classpath,
     )
     return _phase_collect_jars_default(ctx, p, args)
 
 def phase_collect_jars_macro_library(ctx, p):
     args = struct(
-        base_classpath = p.scalac_provider.default_macro_classpath,
+        base_classpath = ctx.toolchains["@io_bazel_rules_scala//scala:bootstrap_toolchain_type"].bootstrapinfo.macro_classpath,
     )
     return _phase_collect_jars_default(ctx, p, args)
 
@@ -58,7 +58,7 @@ def phase_collect_jars_common(ctx, p):
 def _phase_collect_jars_default(ctx, p, _args = struct()):
     return _phase_collect_jars(
         ctx,
-        _args.base_classpath if hasattr(_args, "base_classpath") else p.scalac_provider.default_classpath,
+        _args.base_classpath if hasattr(_args, "base_classpath") else ctx.toolchains["@io_bazel_rules_scala//scala:bootstrap_toolchain_type"].bootstrapinfo.classpath,
         _args.extra_deps if hasattr(_args, "extra_deps") else [],
         _args.extra_runtime_deps if hasattr(_args, "extra_runtime_deps") else [],
         _args.unused_dependency_checker_mode if hasattr(_args, "unused_dependency_checker_mode") else p.unused_deps_checker,